Manually releasable locking means for fuel control means



H. MEACHEM Oct. 17, 1933.

MANUALLY RELEASABLE LOCKING MEANS FOR FUEL CONTROL MEANS Filed June 30, 1931 WWII/III/I/Il/J/IIII/ INVENTOR fi'arry flint/rem BY Hi ATTORNEY v LIV/6 Patented Oct. 17, 1933 V UNITED STATES PATENTLOFFICEQ I 1,930,901 I MANUALLY RELEASABLE LOCKING. MEANS FOR FUEL CONTROL MEANS Harry Meachem, Teaneck, N. 1., as signor to Todd Dry'Dock, Engineering & Repair Corporation,

Brooklyn, N. Y.

Application June 30, 1931. Serial No. 547,901

2 Claims.

This invention relates to furnaces employing a. blower to create the primary air supply, and hav ing a magnetic valve, of thesolenoid type, for controlling the supply of fuel to the furnace.

In my earlier patent application, Serial No. 530,178, filed April 15, 1931, Patent No. 1,873,656 of August 23, 1932, I have described means whereby pressure of air. from the blower casingserves as the power medium for opening the damper to admit secondary air to the furnace,said power medium operating against gravity means whose function it is to close said damper when the blower pressure is shut down.

Also, in my companion case, Serial No. 547,902, filed June 30, 1931, while employing the same or corresponding instrumentalities for opening and closing the damper for control of the secondary air supply, I have disclosed means for actuating the means whereby the fuel supply is controlled, to the end that said fuel supply be automatically shut off when the blower pressure ceases, and also that the fuel supply to the furnace may become automatically re-established when the blower is again operating to deliver the primary air at efficient pressure.

In said companion case it is predicated that a pilot flame is employed to ignite the fuel mixture upon re-establishment of the blower pressure and the fuel supply.

However, in the instance not equipped with a pilot flame and wherein the fuel mixture is to be ignited by a hand torch, it is desirable that when the blower is shut down and the fuel supply at the same time out off automatically, means shall be provided that will necessitate a manual operation to re-establish the fuel supply, to thereby avoid the continued flow of fuel into the furnace.

Therefore my present invention includes locking means which automatically come into operation, upon the cessation of blower pressure, to lock the fuel supply control means in its fuel shut-01f position, said locking means requiring a r manual operation for its release and re-establishment of the fuel supply.

Other features and advantages of my invention will hereinafter appear.

In the drawing: Figure l is a front view of a furnace, having a hollow front, or air box, with a damper, and provided with a blower, and a motor, also having damper control means and magnetic, fuel supply control means, together with automatic means 55; for the operation of the fuel supply control means,

of a furnace that is and my improved meansfor locking said supply means in its shut off position.

Fig. 2 is a top plan view of the air pressure cylinder employed in the operation of the fuel supply control means, including the locking device.

Fig. 3 is a and Fig. 4 is a side sectional view of .Fig, 3.

In the drawing let 1 indicate a furnace which may be equipped with suitable fuel burning means, (not shown) and let 2 indicate,a=hol-low front, or air box, having the damper 3 to control the inlet for secondary air supplies.

At 4 there appears a blower, which is operated by a motor 5, for delivering the primary air supply under pressure to the fuel burning means.

The parts thus far referred to are of usual character.

As in my earlier application for patent, Serial No. 530,178, filed April 15, 1931, a vertically disposed cylinder 6 is attached to the blower casing, said cylinder having its upper end open and containing a piston 7; and, also as in said earlier application, the bottom of cylinder 6 is connected, as by a pipe 8, with the interior of the blower casing, so that when the blower is operating, pressure therefrom will pass to the cylinder to raise the piston therein.

The piston is connected, as by a flexible connector 9, with one end of a beam 10, which is here shown as pivotally mounted on a bearing stud 11 that projects from the blower casing, and the other end of said beam connects, as by a flexible connector 12, with a crank 13, whose shaft 14 carries the damper 3, for the operation of said damper.

The weight of piston 7 exceeds that of damper 3, so that when there is no pressure in cylinder 6 the piston will fall by gravity to the cylinder bottom, and in that position it by my improved locking means, thereby holding the damper in its closed position, and, as will hereinafter appear, also'locking the fuel supply control means to shut off the delivery of fuel.

There is depicted at 16 a usual form of magnetic valve for controlling the supply of fuel to the furnace, and, included in the same electrical circuit is a mercury switch 17, which is supportsection on the line 33 of Fig. 2,

ed upon the beam 10, the function of said switch 105 being to close and open the circuit for the operation of the valve, according to the direction of tilt accorded the beam 10. The valve and switch, with the electrical circuit, are more fully described in my aforesaid companion case.

is to be held locked Also in this application the pressure raising of piston 6 tilts the beam in one direction to close the circuit, thereby causing the damper to open and the fuel supply to also open, and the cessation of pressure in cylinder 6 permits the piston to fall, thereby causing the switch to open the circuit and consequently effecting the closing of the fuel supply and the damper.

But with the fuel thus shut off, and in the absence of a pilot flame, I provide a lock member in the form of an arm 18 that is in pivotal engagement at its lower end with the piston 7, as at 19, and extends upwardly therefrom through a slot or opening 20 provided in the cover 21 for cylinder 6. The arm 18 is shown'as tapering downwardly, and as provided toward its upper end with the opposite shoulders 22, which are adapted respectively to engage against the under surface of cover 21 when the piston has fallen to the bottom of cylinder 6, to thereby prevent said piston from rising when blower pressure is again applied, until said arm 18 has been manually released vfrom such engagement. Arm 18 has an upper extension 23 adapted to co-act with the edges of slot 20 when the piston is lowered, and serving as a handle whereby an attendant can release the lock.

It is due to the pivotal support of arm 18 at its lower end, and its top heaviness that it tends to incline to one side or the other in slot 20, and thus, as the piston descends to the point where one of the shoulders 22 has passed through the r slot, that shoulder will assume a position opposed to the under surface of cover 21 and thereby the piston will be locked in its down position. Or if desired the arm 18 can be pivoted off centre to provide excess weight at one side to thereby assure its falling over on that side.

Variations within the spirit and scope of my invention are equally comprehended by the foregoing disclosure.

1 claim:

1. A device of the character described comprising a cylinder, a piston slidably mounted within said cylinder, said cylinder having an apertured top, and an arm pivotally borne by said piston extending through said aperture and presenting a shoulder to engage against the undersurface of the top of said cylinder when said piston has fallen to the bottom of said cylinder, thereby maintaining said piston in an extreme position.

2. A device of the character described comprising a cylinder having a slot in its top, .a piston slidably mounted within said cylinder, :an arm pivotally borne by said piston and having an extension projecting through the slot in said cylinder top and a shoulder arranged below said extension to engage against the undersurface or said cylinder .top when the piston has fallen to the bottom of said cylinder, :thereby locking said piston at the bottom of said cylinder, said extension being manually-operableto re'leasesaid shoulder to permit movement of said piston.

- HARRY MEACHEM. 

